1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to manufacturing an electroactive polymer actuator, and more particularly, to manufacturing an electroactive polymer actuator using deformation layers having a multilayer structure.
2. Description of the Related Art
Recently, actuator technologies using electroactive polymers (EAPs) have become widespread, and EAPs are often referred to as artificial muscle actuators due to the similarities with human muscles.
EAPs are polymers whose shape is modified when electronic stimulation is is applied to them. They can be used a sactuators or sensors. Polymers can be actuated not only by electronic stimulation, but also bychemical stimulation, heat, or other types of stimulation. EAPs can have several configurations, but are generally divided in two principal calsses: (1) electronic EAPs, in which actuation is caused by electrostatic forces between two electrodes whci squeeze the plymer (e.g., dielectric elastomers and electrostrictive polymers); and (2) ionic EAPs, in which actuation is caused by the displacement of ions insider the polymer. Examples of ionic EAPs are ionic polymer metal composites (IPMCs), conductive polymers, ionic polymer gels, polyvinylidene fluoride (PVDF), carbon nanotubes, and shape memory polymers. Some of EAPs are actuated in a liquid such as a chemical solvent and others are actuated in the air by electric energy.
Increasingly, there are efforts to reduce the size, mass, and power of actuators as well as use them to operate biologically inspired devices. Electroactive ceramic actuators (for example, piezoelectric and electrostrictive) are effective, compact actuation materials and they are used to replace electromagnetic motors. However, while these materials are capable of delivering large forces, they produce a relatively small displacement on the order of magnitude of fraction of a percent. For high-performance camera modules suitable for mobile devices, which have auto-focus and zoom functions, actuators of large displacement are required. A conventional ceramic piezoelectric actuator can be deformed to reach the maximum ratio of deformation of 0.1%, but a polymer actuator is capable of reaching approximately 5%. However, during the operation of the a polymer actuator, a difference in the deformation of an elastomer and the deformation of a metal electrode causes delamination or performance degradation, which in turn is detrimental to reliability of the product. Additionally, in order to maintain the performance of the polymer actuator while reducing the driving voltage, there is a need for technologies to laminate thin actuators into a multilayer structure.